Rework image to use s6-overlay to run TMServer and Xaseco

- Adds S6-Overlay
- Bundles Xaseco into the image

Dockerfile

@@ -0,0 +1,24 @@
+FROM php:5.6-alpine
+ARG S6_OVERLAY_VERSION=3.1.1.1
+
+RUN apk add --no-cache pwgen gettext xmlstarlet bash xz
+RUN docker-php-ext-install mysql
+
+COPY tmserver/ /var/lib/tmserver
+COPY xaseco/ /var/lib/xaseco
+
+RUN addgroup -S trackmania && adduser -D -H -S trackmania -G trackmania
+RUN chown -R trackmania:trackmania /var/lib/tmserver /var/lib/xaseco
+
+EXPOSE 5000
+
+CMD ["/var/lib/tmserver/entrypoint.sh"]
+
+ADD https://github.com/just-containers/s6-overlay/releases/download/v${S6_OVERLAY_VERSION}/s6-overlay-noarch.tar.xz /tmp
+RUN tar -C / -Jxpf /tmp/s6-overlay-noarch.tar.xz
+ADD https://github.com/just-containers/s6-overlay/releases/download/v${S6_OVERLAY_VERSION}/s6-overlay-x86_64.tar.xz /tmp
+RUN tar -C / -Jxpf /tmp/s6-overlay-x86_64.tar.xz
+ENTRYPOINT ["/init"]
+
+RUN touch /etc/s6-overlay/s6-rc.d/user/contents.d/xaseco
+COPY services.d/xaseco/ /etc/s6-overlay/s6-rc.d/xaseco/